isA = True;
type_a = type(True);
print(isA, type_a); # True <class 'bool'>  大写的True  False
# ==  !=   运算符
isR = 10>= 5;
isC = 10 != 3;
isS = 'abc' == "abcd"
print(isR);
print(isC);
print(isS);
# if elif 很有意思 根据4个缩进来判断归属，嵌套if 也要注意缩进
if 10 == 5 :
    print("10 == 5")
elif 10<5 :
    print("10 < 5")
else:
    print("10 > 5")
i= 0;
while i< 3:
     print('while \t循环', i);
     print("hah \tdsf")  # 制表符可以对齐内容
     i+=1;

print()
for i in range(3):  # range(num)  生成数字序列
    print(i);
print()
for i in range(3, 15, 3):  # range(start, end, step)  生成数字序列
    print(i)
print()
str_adf = "adfasdf"
for i in str_adf:
    print(i);